Fuel-injection device for internal-combustion engines



w 7 1,638,032 K. HlMME LSBACH FUEL INJECTION DEVICE FOR INTERNALCOMBUSTION ENGINES Filed F6b.26. 1925 Patented Aug. 9, 1927.

UNITED STATES PATEN OFFICE.

KARL HIMMELSIBACH, OF ESSEN, GERMANY, ASSIGNOR TO FRIED. KRUPP A K'IIEN-GESELLSCHAFT, OF ESSEN-ON-THE-RUHR, GERMANY.

FUEL-INJECTION DEVICE FOR INTERNAL-COMBUSTION ENGINES.

Application filed February 26, 1925, Serial No. 11,813, and in GermanyFebruary 27, 1924.

This invention relates-to internal combustion engines and has particularreference to engines of the type in which the fuel is injected into thecylinder directly by the fuel pump without the use of compressed air,the

opening of the fuel valve being affected automatically by the pressureof the liquid fuel during the pressure stroke of the fuel pump.

In well-known engines of this kind the upper portion of the valve needleis formed as a steering piston which is ground in the valve casing.Owing to this arrangement which renders a yielding of the guided portionimpossible, it is diflicult to attain an accurate centering of the lowerneedle portion constituting the valve proper with relation to theconical valve seat, especially so if the seat is disposed in a partwhich is separate 1 from the casing and which while in screwthreadedconnection with the casing does not at the same time serve as a guidefor the valve needle.

The invention has for its object to obviate the said drawback and toprovide a device by which a good centering of the valve needle on thevalve seat is always secured, the ob ject being essentially attained byforming the lower portion of the valve needle as a special piece whichis connected with the upper needle portion in such a manner that it isnonshiftable in axial direction while it is movable radially in alldirections so that it is adapted to always adjust itself centricallywith relation to its hollow cone-shaped seat under the action of thevalve spring.

An embodiment of the subiect-matter of the invention is illustrated inthe accompanying drawing which shows a longitudinal section through afuel injection device con- L0 structed in accordance with the invention.

The casing A is provided with a cylindrical bore a in which is mountedfor reciprocatory motion the upper part B of the valve needle whichforms a steering piston.

5 The piston is tightly ground in and placed under the action of thevalve spring C arranged above it. The admission of the fuel takes placethrough a channel a arranged in the casing A. The casing has screwed onits lower end a pot-shaped member a the bottom of which contains thehollow conical seat and the nozzle bore a opening into the seat.According to the invention the needle valve 1) proper is a special pieceseparated from the piston B. It possesses at its upper end a collar 22and is connected with the piston B by a cap nut D which by its innerflange d grips with lateral playbehind the collar 6 The nut D istightened so much that the two parts B and I) bear against each other inaxial direction without any play, while the part b is allowed to movewith relation to the partB radially in all directions. Thereby it isattained that the needle valve 6 is always pressed exactlyconcentrically on the valve seat under the action of the valve spring C.

There may be used instead of the cap nut D a correspondingly shapedsleeve pressed on or connected in any other suitable manner with thepart B.

Claims:

1. A fuel injection device for internal combustion engines of the kindreferred to, consisting of a fuel valve comprising a casing, a valveneedle and a conical seat for the needle, the valve needle being made upof two superimposed separate parts, the upper part constituting aspring-pressed steering piston mounted for reciprocation in the casingand the lower part forming the valve proper, and means connecting thetwo needle parts in such a manner as to hold them against tiltingmovement with relation to each other, but to allow the lower part tomove ra'dially with relation to the upper part in all directions so thatthe valve will always adjust itself centrically to its seat under theaction of the valve spring.

2. A-fuel injection valve for internal combustion engines comprising acasing, a valve needle and a conical seat for the needle, the valveneedle being made up of two superimposed separate parts with abuttingsurfaces, at least one of which is flat, the upper part constituting aspring-pressed steering piston mounted for reciprocation in the casingand the lower part consisting of a stem and a collar forming the valveproper, and a perforated cap nut screwed on t e lower end of 109 theupper part and receiving within it the tact with each other to preventtilting of the collar of the lower part, the stem extending lower partwith respect to the upper art. out through the perforation, theperforation The foregoing specification slgne at 10 being of greaterdiameter than the stem to Essen, Germany, this 21st day of January 5permit lateral motion thereof, and the cap- 1925.

nut being adapted to hold the abutting surfaces of the upper and lowerparts in con- KARL HIMMELSBACH.

